39845621213 has 4 divisors (see below), whose sum is σ = 39847665468. Its totient is φ = 39843576960.

The previous prime is 39845621209. The next prime is 39845621269. The reversal of 39845621213 is 31212654893.

It is a semiprime because it is the product of two primes.

It can be written as a sum of positive squares in 2 ways, for example, as 23409612004 + 16436009209 = 153002^2 + 128203^2 .

It is a cyclic number.

It is not a de Polignac number, because 39845621213 - 2² = 39845621209 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (39845621203) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 992606 + ... + 1031967.

It is an arithmetic number, because the mean of its divisors is an integer number (9961916367).

Almost surely, 2^39845621213 is an apocalyptic number.

It is an amenable number.

39845621213 is a deficient number, since it is larger than the sum of its proper divisors (2044255).

39845621213 is a wasteful number, since it uses less digits than its factorization.

39845621213 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 2044254.

The product of its digits is 311040, while the sum is 44.

The spelling of 39845621213 in words is "thirty-nine billion, eight hundred forty-five million, six hundred twenty-one thousand, two hundred thirteen".